Digital Panel Meter Specifications

Dependable Calibration

Three calibration methods are selectable: scale and offset, two-point, and system-level (using actual transducer signals).  All ranges are precalibrated at the factory, with calibration factors for each range stored in nonvolatile EEPROM.

Recalibration is therefore unnecessary when changing ranges in the field.  for temperature meters, data display in °C or °F is selectable from the front panel.

All versions of the DC Voltage, DC Current, Process Signal, and Strain Gage Meters allow easy setting of scale and offset by either of two methods:

• With the coordinate reading method, the meter reads the high and low signal values, and the user enters the desired high and low reading values.  The meter then calculates the appropriate span multiplier and offset.  This method is ideal if an external calibration reference is available.
• With the manual coordinate method, the user enters the high and low input values in volts, plus the desired high and low reading values.  This method is suitable in the absence of an external calibration reference.

High-Speed A/D Conversion

A unique Concurrent Slope A/D technique yields 60 conversions per second (50 for 50-Hz operation), while integrating over a full cycle of the line for maximum noise reduction.  Self-calibration cycles reduce the average reading rate only slightly, to 56 per second (47 for 50 Hz).  This exceptionally fast read rate provides an accurate display of peak signal input and quick response in control applications.

Selectable Signal Filtering

Data readings and outputs can be separately selected to be either filtered or unfiltered.

• An unfiltered selection updates after each conversion for fastest response, up to 60/sec, while integrating the input signal over a full power cycle.  Fast read rate provides true peak readings and aids in control applications.
• A batch average filter selection averages each 16 conversions for an update every 1/4 second.
• An adaptive moving average filter selection provides a choice of 8 time constants from 80 ms to 9.6 s.  When a significant change in signal level occurs, the filter adapts by briefly switching to the shortest time to follow the change, and then reverts back to its selected time constant.
• Another choice is Autofilter, which automatically selects the best time constant for the existing level of signal noise, ensuring stable displayed readings and outputs, while responding rapidly to changes of the input signal that exceed a selected threshold value.

Advanced Meter Features

The peak value of the input can be displayed at the push of a button, or on receipt of a control signal at the rear connector (since the last meter reset).  Other controls via the rear connector include meter hold, meter reset, peak reset, and decimal point selection (see Specifications, below).

Auto-tare capability allows the display to be instantly zeroes for any input signal.  This is a standard practice in weighing applications, to subtract out the weight of the container.  The tare offset is normally achieved by applying a switch closure or logic signal at the rear connector.  The tare value is stored in nonvolatile memory and is therefore retained on loss of power.

"Extended" DPM

An optional "Extended" DPM version allows extremely accurate custom linearization of a nonlinear input signal such as a thermistor or altimeter reading, or the level or pressure reading of lique in an irregularly shaped tank.  It is also capable of measuring and displaying rate of change (as, for example, in flow rate measurements).  Contact the factory for further information on this option.

There are specific panel meter models for:

Input signals may be displayed as voltage or current, or be scaled from the DPM front panel to five full digits (from -99,999 to +99,999), to read directly in engineering units such as PSI.

General Digital Panel Meter Specifications